Project Summary Cardiovascular disease (CVD) is a major cause of morbidity and mortality in adults living with HIV (ALHIV), and cigarette smoking is the single most important modifiable CVD risk factor in this population. Success rates for existing smoking cessation interventions are relatively low. Poor sleep is more prevalent among smokers, more prevalent among ALHIV, can be caused by smoking cessation attempts, predicts relapse to former smoking patterns, and represents a parallel pathway to morbidity including increased cardiovascular disease (CVD) among ALHIV. Thus, unhealthy sleep may make smoking cessation more difficult and increase cardiovascular risk and other poor health conditions in ALHIV. Yet, poor sleep is amenable to nonpharmacologic interventions, and a pilot study from our group revealed that a sleep health intervention increased smoking cessation rates when added to routine smoking cessation treatment. The mechanisms by which improvements in sleep health enhance tobacco cessation are unknown, but improved cognitive and affective functioning are two candidates. To evaluate the efficacy of our sleep training approach to improve sleep health and increase smoking cessation rates in ALHIV, the proposed study will supplement an empirically-supported smoking cessation program (6- session, 15-week counseling program with varenicline) with a Sleep Training Approach to Reducing Smoking (STARS) intervention developed for smokers. This intervention uniquely addresses (1) existing sleep difficulties, if any, prior to quitting that may be associated with HIV status or nicotine use; (2) inoculation against future sleep difficulties brought on by quitting and/or varenicline; (3) acute intervention on sleep efficiency and duration as the participant progresses through the program; and (4) development of healthy sleep habits to carry forward beyond the intervention. This approach is based on the gold-standard approach to treating insomnia (Cognitive Behavioral Therapy for Insomnia) but includes a number of novel elements tailored to this population. STARS will be compared to a General Health (GH) educational control. The study will recruit N=200 ALHIV smokers who are interested in quitting. They will be randomized to smoking cessation with either STARS (N=100) or GH (N=100). The study will measure the efficacy of STARS versus GH to improve objectively measured healthy sleep metrics, assess its impact on smoking cessation as well as other metrics of CVD risk, and determine whether cognitive and affective variables mediate the association between sleep health and smoking cessation. Results of these studies will provide practical information as well as mechanistic insight into how sleep health can be leveraged to optimize smoking cessation treatment in ALHIV.